Electronic devices used to receive broadcast signals, such as audio radios, often facilitate the user's control of the device by providing programmable operator interface keys. In the case of radios, a number of programmable “preset keys” are usually provided that allow a user to assign a particular radio channel to each of the programmable preset keys. These preset keys are especially useful for the use of radios in an automobile where it is desired to minimize a driver's distraction in selecting a different received radio channel. Preset keys are also used in portable radios and in all types of radios due to their general convenience. Once a channel is assigned to a preset key, the user is able to cause the radio to select that channel by simply pressing the preset key to which that channel is assigned. By assigning different channels to each preset key, the user is able to quickly select a number of favorite channels by simply pressing the associated preset key.
Advances in technology allow an increasing number of preset keys to be provided on a single radio. The user interfaces of such radios typically do not display, in a comprehensive or convenient manner, the channels that are assigned to all of the preset keys. A user wishing to determine which channels are assigned to the preset keys is usually required to press each preset key and remember which channels are assigned to each. This becomes increasingly difficult as the number of preset keys increases. Furthermore, radios typically do not indicate which preset keys have channels already assigned. When a user wishes to assign a new channel to a preset key, there is no way to easily confirm which preset keys is not already assigned a channel that is desired by the user and which the user does not wish to overwrite with the new channel. This often requires a user to sequence through all preset keys to determine which preset key can be overwritten with the assignment of the new channel. The user is also not sure, unless the user inspects the setting of all of the preset keys, if the “new” channel is already assigned to a preset key.
New radios signals are digitally modulated and may require a significant amount of time to process the signal. This can result in a delay when a radio's signal processor is changed to another channel. This delay can produce an undesirable gap in the programming presented to the user.
Therefore a need exists to overcome the problems with the prior art as discussed above.